JP2003311847A - Method of manufacturing center belt for heavy load transmission belt - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method capable of preventing a clearance to be formed at the joint part of a center belt and the occurance of a groove and an unevenness, and reducing failure and a scrap portion. <P>SOLUTION: In the method for manufacturing the center belt used for a heavy load transmission belt comprised of a plurality of fitted and fixed blocks along a longitudinal direction of the center belt, a composite sheet H, wherein a cover canvas C1 is coated on the surface of a rubber sheet G1 having a concave part, is temporarily fixed by a temporary fixing tape T comprised of a same kind of the rubber as the rubber sheet G1 in a butt state, wrapped in a core wire, further coated with the rubber sheet and vulcanized. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high load transmission belt used for applications such as continuously variable transmissions such as automobiles, motorcycles, agricultural machinery, etc., in which blocks are arranged in a longitudinal direction on a center belt. It is a method of manufacturing a center belt, and facilitates the work of the butt joint of the rubber sheets when manufacturing the center belt,
The present invention relates to a method that enables a more stable joint.

[0002]

2. Description of the Related Art A belt used in a belt type continuously variable transmission is used by being wound around a variable speed pulley in which the effective groove diameter of the pulley is changed by changing the V groove width of the pulley to adjust the gear ratio. However, since the lateral pressure from the pulley increases, the belt must withstand the large lateral pressure. Further, in addition to the use of continuously variable transmission, it is necessary to use a belt that can withstand a particularly high load for a high load transmission application in which the life of a normal rubber belt is too short.

Among such belts used is a high-load transmission belt in which a block is fixed to a center belt to increase the strength in the belt width direction. As a concrete structure, a core is made of rubber or the like. No. 63-34342, in which a block relatively harder than the rubber used in the center belt is fixed and fixed to the center belt embedded in the rubber by using a fastening material such as bolts and rivets. As shown, there is a belt which has grooves on both side surfaces of the block and in which a pair of center belts are fitted in the grooves provided on the side surfaces.

The center belt used for such a belt is a member that bears tension, has a core wire of high strength and low elongation embedded in rubber, and is fitted to a block on the inner and outer peripheral surfaces of the center belt. The concave portions and the convex portions are alternately provided. For example, convex portions are provided in the grooves on both side surfaces of the block at positions corresponding to the concave portions of the center belt, and when the blocks are fitted to each other, the blocks do not move in the traveling direction of the high load transmission belt with respect to the center belt. It is fixed.

A cover canvas is laminated on the surface of the center belt for reinforcement. In addition, such a center belt is formed by winding a rubber sheet having a recessed portion that fits with a block having a predetermined pitch on the lower surface and a cover-cloth laminated endless composite sheet around a cylindrical mold to joint the ends. By doing so, the joint is made endless, and the joints of the composite sheet are butted to each other in order to make the pitch of the concave stripes constant.

[0006] Specifically, when the cover canvas and the rubber sheet are wound around the mold, the adhesive tape such as cellophane tape is used to temporarily fix at 2 to 4 places, and the fiber material rope Wrap the core wire consisting of
Furthermore, if necessary, a method of winding a rubber sheet and a cover canvas from above to vulcanize is adopted.

[0007]

However, since the adhesive tape used for temporary fixing becomes a foreign substance, the portion to which the adhesive tape is attached cannot be used as a product. For example, when the center belt sleeve is cut into a predetermined width after molding and vulcanization, it must be removed as a defective or scrap portion.

Therefore, if too many adhesive tapes are attached at the time of temporary fixing, the center belt will be scraped by the amount of the adhesive tapes attached, so the number of places for temporary fixing with the adhesive tapes should be minimized. It is preferable.

However, on the contrary, if there are too few temporary fixing points, the abutted portions will be peeled off and a gap will be formed between the ends of the rubber sheet at the joint portion. There was a problem that peeling occurred on the surface, resulting in a groove or a step.

Further, once the core wire is wound, temporary fixing becomes unnecessary. Therefore, a method of peeling off the adhesive tape in sequence in the step of winding the core wire is conceivable. The problem of dust being generated can be solved. However, in terms of work, it is a dangerous task to peel off the adhesive tape from the rotating mold, and if safety is emphasized, the winding of the core wire may be temporarily stopped to peel off the adhesive tape. Occurs, which causes a decrease in efficiency.

Therefore, the present invention solves the above problems and manufactures a center belt for a high load transmission belt.
When wrapping the cover canvas and rubber sheet around the mold and making a butt joint, you can easily temporarily fix it, and even if the center belt is molded and vulcanized as it is, it will not be defective or waste, and it will be a butt joint. An object of the present invention is to provide a method for manufacturing a center belt for a high load transmission belt, which can prevent the generation of a gap due to peeling in a portion and the generation of a groove or a step.

[0012]

In order to achieve the above object, in claim 1 of the present invention, a center belt having a core body embedded in rubber, and a plurality of center belts are fitted along the longitudinal direction of the center belt. A center belt used for a high-load transmission belt composed of fixed and fixed blocks, at least the inner peripheral side of which is composed of a composite sheet in which the surface of a rubber sheet having recesses in the width direction is provided at a predetermined pitch and covered with a cover canvas. A center for a high load transmission belt having a step of vulcanizing the composite sheet by abutting and temporarily fixing it in a state of being wound on an inner die, and heating and pressurizing it in a state of winding a core wire from above. In the belt manufacturing method, when the composite sheet is wound around the inner mold, the joints are abutted and a temporary fixing tape made of the same type of rubber as the rubber sheet is attached to the surface. Characterized in that it temporarily stopped by.

By using a temporary fixing tape made of the same kind of rubber as the rubber sheet, the rubber sheet and the temporary fixing tape can be fitted well and can be reliably fixed temporarily, so that a gap is formed in the joint portion or a groove or a step is formed. The rubber sheet and the temporary fixing tape are vulcanized and integrated so that they do not become foreign matter and can be used as a normal center belt as they are. Since it is not necessary to remove the temporary fixing tape in the process of spinning the wire, the manufacturing efficiency is not reduced.

In the present invention, the thickness of the temporary fixing tape is 0.
The manufacturing method of the center belt for the high load transmission belt is in the range of 1 to 0.3 mm.

By using the temporary fixing tape having a thickness in such a range, the temporary fixing tape has a sufficient strength for the purpose of temporary fixing, and the thickness of the center belt is affected, and when the high load transmission belt is formed, the running belt is run. There is no adverse effect on performance.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below with reference to the drawings.

FIG. 1 is a perspective schematic view showing an example of a high load transmission belt 1 using a center belt manufactured by the method of the present invention, and FIG. 2 is a sectional view of the center belt. A high load transmission belt 1 using a center belt manufactured by the method for manufacturing a center belt for a high load transmission belt of the present invention has a rubber-like core 5 having a rope-shaped core body 5 embedded in a spiral shape and having the same width. Two center belts 3a,
3b and center belts 3a and 3b on the side surfaces 2a and 2b.
It is composed of a block 2 having grooves 14 and 15 in which are fitted.

Upper and lower surfaces 2 of the center belts 3a and 3b
It is locked and fixed in the groove portions 14 and 15 of the block 2 in the groove portions 18 and 19 formed at a predetermined pitch in the groove portions 2 and 23 as described later. Both side surfaces 2a, 2b of the block 2 are inclined surfaces that engage with the V groove of the pulley, and receive the power from the driven pulley to lock and fix the center belt 3
Power of the drive pulley is transmitted to the driven pulley by pulling a and 3b. Further, canvases 24 and 25 are laminated on the upper and lower surfaces of the center belts 3a and 3b.

As shown in FIG. 1, the block 2 includes an upper beam portion 11 and a lower beam portion 12, an upper and lower beam portions 11,
The center pillars 13 are formed by connecting the central portions of the blocks 12 to each other.
Grooves 14 and 15 into which a and 3b are fitted are formed. Further, as shown in FIG. 2, on the groove upper surface 16 and the groove lower surface 17 in the groove 15, there are convex stripes that engage with the concave stripes 18 provided on the upper surface 22 of the center belt 3 and the concave stripes 19 provided on the lower surface 23. Part 2
0, 21 are provided so that the block 2 and the center belts 3a, 3b are locked and fixed.

As shown in FIG. 2, the center belts 3a and 3b have a core body 5 buried substantially in the center in the thickness direction of the center belt, and are located on the inner layer 4a located on the inner peripheral side and on the outer peripheral side thereof. It consists of an outer layer 4b.

Such a center belt for a high load transmission belt is manufactured by the following steps. FIG. 3 is a side view of the joint of the composite sheet H on the inner die. The inner layer 4a has a cover canvas C on one side of the rubber sheet G1.
The rubber sheet G1 is made to have a thickness larger than a predetermined thickness by first rolling, and the cover canvas C1 is laminated. Then, a concave streak portion 1 for fitting the block on the surface where the cover canvas C1 is laminated by pressing
Composite sheet H which becomes inner layer 4a by forming 9
Is completed.

Next, the composite sheet H is wound around an inner mold 40 having a cylindrical shape and having a convex shape which is fitted around the concave stripe portion of the composite sheet H. As shown in FIG. 4, the core wire 5 is spirally wound from above, and the rubber sheet G2 and the cover canvas C2 which will be the outer layer 4b are further wound from above. Then, the center belt 2 is completed by covering the inner surface with an outer mold (not shown) having a convex shape as needed and vulcanizing by heating and pressing.

The method of heating and pressurizing is not particularly limited, and may be a method of covering with a jacket and placing it in a vulcanization can by steam, or a method of using a mold further provided with an electric heater from the outside. I do not care.

In the present invention, the composite sheet H is wound around the inner mold 40 to form the butt joint J. When the composite sheet H is wound around the inner mold 40, a temporary fixing tape made of the same kind of rubber as the rubber sheet G1 is used. Use T to temporarily secure in a butt shape. Conventionally, an adhesive tape such as a tape made of cellophane was used to temporarily fix the composite sheet H at 2 to 3 places, but since the material such as cellophane is a foreign substance to the center belt, it is temporarily fixed with the adhesive tape. The part that had been used could not be used as a product and was a waste part. In the present invention, since the same type of rubber as the rubber sheet forming the center belt is used as the temporary fastening tape T, the temporary fastening tape is integrated as it is with the rubber sheet G1 and becomes a part of the center belt. The part that has been made can also be used as a product.

The thickness of the temporary fixing tape T is 0.1
It is preferable to use one having a thickness of 0.3 mm. If the thickness is less than 0.1 mm, the strength is not sufficient and the temporary breakage occurs due to the breakage of the tape, which causes a problem such as a gap in the joint J, which is not preferable. Also, 0.3 mm
If the thickness exceeds the range, the thickness of the center belt will not be negligible when it is vulcanized and integrated into the rubber sheet G1, and it will be involved in the fitted state of the center belt and the block. It is not preferable because it may lead to adverse effects.

A rubber sheet G as a material for the temporary fastening tape T
Although the same kind of rubber as that of No. 1 is used, other compounding agents and compounding ratios may be slightly different as long as the polymers are basically the same.

What is used as the rubber 4 of the center belts 3a, 3b is a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, or a rubber or polyurethane in which these are appropriately blended. Examples thereof include rubber and the like, and carbon black, a plasticizer, a filler, a short fiber and the like are blended with these rubbers as needed. On the other hand, the temporary fixing tape T can surely perform the temporary fixing by using the same kind of polymer as the material forming the center belt as described above, and can be integrated without becoming a foreign substance after vulcanization. it can. For example, if the rubber used for the center belt is nitrile rubber, nitrile rubber is also used for the temporary fastening tape T. In the case of blended rubber, at least one polymer may be common. If the polymers are the same as described above, the other compounding agents need not be exactly the same, and the compounding amounts may be different.

In the present invention, the temporary fixing tape T made of the same kind of rubber as the rubber sheet G1 is used for temporarily fixing the joint portion J of the composite sheet H when forming the inner layer 4a of the center belt. The purpose of the present invention is to prevent the generation of scraps and the formation of grooves and steps by using an adhesive tape as a foreign substance in the joint J, and to limit the other steps in the manufacturing process. Absent.

The high load transmission belt 1 can be finally obtained by fitting the block 2 into the recessed portions 18 and 19 of the center belt obtained as described above.

FIG. 5 shows an example of another belt to which the center belt obtained by the manufacturing method of the present invention can be applied, in which the pair of side pillars 32 and 33 are arranged upward from both ends of the beam portion 31. It extends and this side pillar 3
Lock parts 34 and 35 extending from the upper ends of the blocks 2 and 33 toward the center of the block 2 are provided so as to face each other. And these beam part 31 and side pillar 3
A fitting groove 30 into which the center belts 3a and 3b are fitted is formed by the reference numerals 2, 33 and the lock portions 34, 35.
The center belts 3a and 3b are inserted into the fitting groove 30 through the opening between the lock portions 34 and 35 and mounted. Further, on the fitting groove 30 side of the lock portions 34 and 35, the convex portion 37 is provided.
Are provided in the center belts 3a and 3b at predetermined pitches.
Fit to 6. As a result, the center belts 3a, 3
After mounting, b is in a state where it is hard to come off from the block 2.

Further, it is possible to use either a block in which an insert material made of, for example, an aluminum alloy is embedded in the block or a block in which the insert material is not embedded.

Polyamide resin, polyamideimide (PAI) resin, polyphenylene sulfide (PPS) resin, polybutylene terephthalate (PBT) resin and polyimide (P) can be used as the block resin.
Synthetic resins such as I) resin, polyether sulfone (PES) resin, and polyether ether ketone (PEEK) resin are used. Among them, they have a low friction coefficient, excellent wear resistance, rigidity and elasticity against bending. It is preferable to use a resin that has properties and is not easily broken, and a polyamide resin, particularly nylon 46 is preferable.

In the present invention, it is possible to mix a fibrous reinforcing material or a whisker-like reinforcing material in the synthetic resin forming the block as described above, and the fibrous reinforcing material is 15 to 4
It is compounded in the range of 0% by weight. If it is less than 15% by weight, there is a problem that the reinforcing effect is small and the abrasion resistance of the block is not sufficient, and if it exceeds 40% by weight, it becomes difficult to mix it with the resin and injection molding becomes difficult. There is a problem, so it is not preferable.

Examples of the fibrous reinforcing material to be added to the synthetic resin include aramid fiber, carbon fiber, glass fiber, polyamide fiber, polyester fiber and the like. Among them, by using nylon 46, which is a preferable example of the resin forming the block, and carbon fiber in combination, the carbon fiber can improve the water absorption defect of nylon 46 and significantly improve the rigidity, In addition, the wear resistance, impact resistance, and fatigue resistance of nylon 46 can be fully utilized.

In addition to the above organic fibers, inorganic fibers such as zinc oxide whiskers, potassium titanate whiskers and aluminum borate whiskers may be blended as the fibrous reinforcing material.

Further, since the zinc oxide whiskers have a high specific gravity and a high rigidity, vibration at the time of contact with the pulley can be reduced and noise can be reduced. If the amount of this zinc oxide whisker is small, the effect of addition will not be exhibited, and if it is too large, kneading will not be possible and molding will be difficult.

With such a material constitution,
It has strength such as rigidity and toughness that can withstand the lateral pressure that it receives when it comes into contact with the pulley, and it has excellent wear resistance.
Furthermore, it becomes possible to form a block that is strong against heat generated during friction, and the power received from the pulleys can be efficiently transmitted to the center belts 3a and 3b as a tensile force, and a tension transmission type high load transmission belt. Can be configured.

In addition to these, molybdenum disulfide,
The lubricity of the block 2 can also be improved by mixing at least one selected from graphite and fluorine resin. Examples of the fluorine-based resin include polytetrafluoroethylene (PTFE), polyfluoroethylene propylene ether (PFPE), tetrafluoroethylene hexafluoropropylene copolymer (PFEP), polyfluoroalkoxyethylene (PFA), and the like. .

What is used as the rubber 4 of the center belts 3a, 3b is a single material such as chloroprene rubber, natural rubber, nitrile rubber, styrene-butadiene rubber, hydrogenated nitrile rubber, or a rubber or polyurethane appropriately blended with these materials. Examples thereof include rubber. As the core body 5, a rope selected from polyester fiber, polyamide fiber, aramid fiber, glass fiber, steel wire and the like is used.

[0040]

As described above, according to the first aspect of the present invention, a high load transmission including a center belt having a core body embedded in rubber and a plurality of blocks fitted and fixed along the longitudinal direction of the center belt. A center belt used as a belt, which is composed of a composite sheet in which a cover canvas is coated on the surface of a rubber sheet in which at least the inner peripheral side has widthwise recesses at a predetermined pitch, and the composite sheet is wound around an inner mold. In the method of manufacturing a center belt for a high load transmission belt, which has a step of vulcanizing by butting them together and temporarily fixing them, and heating / pressurizing them while winding the core wire from above When the composite sheet is wrapped around the joint, the joint part is abutted and temporarily fixed by sticking a temporary fixing tape made of the same kind of rubber as the rubber sheet on the surface To.

By using the temporary fixing tape made of the same kind of rubber as the rubber sheet, the rubber sheet and the temporary fixing tape can be fitted well and can be reliably fixed temporarily, so that a gap is formed in the joint portion or a groove or a step is formed. The rubber sheet and the temporary fixing tape are vulcanized and integrated so that they do not become foreign matter and can be used as a normal center belt as they are. Since it is not necessary to remove the temporary fixing tape in the process of spinning the wire, the manufacturing efficiency is not reduced.

In the second aspect, the thickness of the temporary fixing tape is 0.
The manufacturing method of the center belt for the high load transmission belt is in the range of 1 to 0.3 mm.

By using the temporary fixing tape having a thickness within such a range, the temporary fixing tape has sufficient strength for the purpose of temporary fixing, and the thickness of the center belt is affected, and when the high load transmission belt is formed, the running belt is run. There is no adverse effect on performance.

[Brief description of drawings]

FIG. 1 is a schematic perspective view showing an example of a high load transmission belt according to the present invention.

FIG. 2 is a side sectional view of a high load transmission belt.

FIG. 3 is a cross-sectional view of a composite sheet wound around an inner mold.

FIG. 4 is a cross-sectional view in which a core body, a rubber sheet on the outer layer side and a cover canvas are further wound around an inner mold.

FIG. 5 is a schematic perspective view showing another example of the high load transmission belt according to the present invention.

[Explanation of symbols]

1 High load transmission belt 2 blocks 3a Center belt 3b center belt 4 rubber 4a inner layer 4b outer layer 5 mind and body 11 Upper beam section 12 Lower beam part 13 center pillars 14 groove 15 grooves 16 groove top 17 Lower surface of groove 18 Recessed part 19 Recess 20 ridge 21 ridge G1 rubber sheet G2 rubber sheet C1 cover canvas C2 cover canvas H composite sheet J joint section

Claims (2)

[Claims] 1. A center belt for use in a high load transmission belt comprising a center belt having a core body embedded in rubber and a plurality of blocks fitted and fixed along the longitudinal direction of the center belt, the center belt having at least an inner circumference. The side consists of a composite sheet in which a cover canvas is coated on the surface of a rubber sheet provided with concave portions in the width direction at a predetermined pitch, and the composite sheet is butted and temporarily fixed by being wound around an inner mold, In the method for manufacturing a center belt for a high load transmission belt, which has a step of vulcanizing by heating and pressurizing the core wire in a wound state, the joint part when the composite sheet is wound around the inner mold is A center bell for a high load transmission belt, which is temporarily fixed by sticking a temporary fixing tape made of the same kind of rubber as the rubber sheet on the surface in a butt state. Manufacturing method. 2. The thickness of the temporary fixing tape is 0.1 to 0.3 m
The method for producing a center belt for a high load transmission belt according to claim 1, wherein the center belt is in the range of m.